Making dimes radioactive was discontinued only when silver coins disappeared from circulation in the mid-1960s. When exposed, the silver in the dimes changed from Ag-109, which absorbed neutrons very easily, to AG-110, which is radioactive. The dimes, for about four minutes, were capable of emitting low-energy beta radiation. After 10 half-life periods, less than a tenth of one percent of the original activity remained and could be detected only by highly sophisticated equipment. . . . the exposed silver transformed itself into stable Cadmium-110."

Based upon the foregoing, I find it hard to believe that "If you have a Geiger counter you can confirm this! Indeed, this was done at an early Fest" as was stated in an earlier Esylum." For this to occur, that dime had to be hit with a LOT more radiation than was being used. I would guess the Geiger counter used at the Fest was picking normal background radiation and not radiation from the dime. Indeed, if you turn a Geiger counter on (as I have done in my geology classes), every now and then it will click. That is from normal background radiation.

Here's scan of my irradiated dime from the NY World's Fair. It is a 1948 Roosevelt dime. I have never removed the dime, so it is the one that I had originally had irradiated.

Here is a scan of my 1951 Roosevelt neutron irradiated dime by the American Museum of Atomic Energy. The reverse is blank. I purchased it from a coin dealer in February 1998 for $5.00.

We tested my two dimes (previously pictured in The E-Sylum) with a Geiger Counter at my college. As predicted, they are not radioactive. Every now and then the Geiger Counter would click. This was due to background radiation. We confirmed this by moving the dimes away from the Geiger Counter and every now & then it would still click.

So anybody who says that their dimes are still radioactive are misinformed or are not familiar with background radiation. In fact, if the dimes were still radioactive then when they were first irradiated the radiation would have been at highly unsafe levels.